Vacuum cup is generally a water container made of ceramic or stainless steel with a vacuum layer. It has a cover on the top and is tightly sealed. The vacuum insulation layer can delay the heat dissipation of liquids such as water inside to achieve the purpose of heat preservation.  The thermos cup is developed from the thermos. The principle of insulation is the same as that of the thermos, but people make the bottle into a cup for convenience.